The present invention relates, in general, to rotary valves, and more particularly, relates to cylindrical or spherical rotary valves having arcuate rotatable diverter elements which are used to direct the flow of fluids through the valve.
Rotary diverter valves are extensively used in swimming pool and spa systems. Such valves are typically driven by a valve actuator and operated in accordance with a sequence controlled by a system controller, for example, a controller of the type set forth in my U.S. Pat. No. 4,322,297. Alternatively, such rotary diverter valves may be manually operated.
Swimming pool diverter valves direct the flow of water between such system elements as the pool, spa, solar heater, gas heater and filter. Such valves are routinely exposed to relatively adverse environments, namely, the flow of heated and chlorinated water through the valve. Accordingly, one of the commonly encountered problems in connection with swimming pool/spa systems has been the lubrication of the diverter valves so that their operation is reliable and does not have high power requirements for the valve actuator.
Although not in use in the swimming pool industry, lubricated plug valves are broadly known. Such valves typically are formed with metal bodies and have a metal plug rotatably mounted therein. The rotatable plug and valve body are conventionally machined to close tolerances and are based upon metal-to-metal contact during motion of the plug within the body. Grooves for the flow of lubricant have been provided in the body housing, and in some instances, in the face of the rotatable plug. In such metal-to-metal diverter valve assemblies, the high pressure seal between the rotating parts is usually effected by the lubricant itself. This is possible because the parts are all metallic and have dimensional stability under high pressure. Typical of such metallic rotary plug valve constructions are the valves disclosed in U.S. Pat. Nos. 1,710,176; 1,861,541; 1,932,322; 2,337,841; 2,388,827; 2,663,290; 2,719,032; and 3,424,190.
A valve of the type used in swimming pool and spa systems is the valve set forth in U.S. Pat. No. 4,470,429. Such valves are formed of high strength plastic materials and include a top or cover plate which allows the valve to be opened and the diverter removed. Approximately every two-to-four months the pool/spa owner or maintenance personnel should remove the valve cover and wipe a lubricant on the diverter and interior of the valve surfaces. As will be appreciated, this maintenance step is often not undertaken, or if the service is provided by a maintenance company, such valve maintenance can be costly.
Problems have also been encountered in connection with the installation of rotary diverter valves in swimming pools/spa systems. Some valves have an undesirably large volume. The valve set forth in U.S. Pat. No. 4,470,429, for example, has a relatively large diameter body in order that the three ports or passageways to and from the valve can be placed at 90 degree intervals about the rotatable axis of the valve. Since swimming pool valves are most preferably used with conventional plumbing fittings, the 90 degree orientation of the valve ports in the valve of U.S. Pat. No. 4,470,429 is highly desirable. Rotation of the ports at 120 degree intervals would permit a reduction in the body size of the valve, but such a valve construction would also require specialized adapter fittings to enable coupling to conventional plumbing fittings, which are constructed for connections at angles which are multiples of 45 degrees.